libksba: Denial of Service and information disclosure

Background

Libksba is a X.509 and CMS (PKCS#7) library.

Description

It was found that an unproportionate amount of memory is allocated when parsing crafted certificates in libskba, which may lead to Denial of Service condition.

Moreover in libksba 1.3.4, allocated memory is uninitialized and could potentially contain sensitive data left in freed memory block.

Impact

A remote attacker, able to interact with an libksba-based application, could possibly obtain sensitive information or cause a Denial of Service condition.

Workaround

There is no known workaround at this time.

Resolution

All libksba users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=dev-libs/libksba-1.3.5"